Be careful out there! A Facebook phishing scam is running rampant this weekend — the third widespread attack on the site in as many weeks. The scheme attempts to steal your Facebook login credentials, install malware on your computer, and grab your home address.

The attack is spread via a “hilarious video” posted to Facebook walls, according to WebSense — when clicked, a form appears requesting your Facebook login:

The attack then returns you to Facebook, installs an app called “Media Player HD”, and asks you to download the “FLV player” — if you do this, malware is installed on your computer. You may also be presented with a contest to win an iPad, with a request to enter your home address.

To avoid getting caught up in this scheme, just remove the “hilarious video” if you find it on your Facebook wall. And if you see it elsewhere on Facebook, make sure you don’t click it. The usual safety rule applies: Don’t enter your Facebook login anywhere other than Facebook.com.

If you’ve already fallen for the scheme, you should immediately change your Facebook password, uninstall the Facebook app (often called “Media Player HD”), and run a virus/malware scan on your computer.

This video from Websense describes the “Most Hilarious Video Ever” attack that began spreading on Facebook on May 28th: